Always throw away any leftovers in which the baby’s licked spoon has dipped. Bacteria is introduced when you put a licked spoon back into a container. 

If your baby is not going to eat a full container, portion out what you think he or she will eat into a separate container and then serve.  The extra thawed food can be stored in a sealed container in the refrigerator for up to 24 hours from the date it was thawed.